How accurate is the US Navy body fat method?

The US Navy method is reasonably accurate for most people and has a typical error margin of 3–4%. It is a convenient alternative to expensive methods like DEXA scans or hydrostatic weighing.

What measurements do I need?

For males: neck, waist, and height. For females: neck, waist, hips, and height. All measurements should be in centimeters.

Yes, completely free with no sign-up required.

Body Fat Calculator

Estimate your body fat percentage using the US Navy method. Enter neck, waist (and hips for females), and height measurements in centimeters.

Sex

Neck (cm)

Waist (cm)

Height (cm)

What is a Body Fat Calculator?

This calculator estimates body fat percentage using the US Navy circumference method, which uses body measurements instead of equipment like calipers or DEXA scans.

US Navy Method formula

Male: % = 495 / (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450

Female: % = 495 / (1.29579 − 0.35004 × log10(waist + hips − neck) + 0.22100 × log10(height)) − 450

All measurements are in centimeters.

Body fat categories

Category	Men	Women
Essential Fat	< 6%	< 14%
Athletic	6–13%	14–20%
Fitness	14–17%	21–24%
Average	18–24%	25–31%
Obese	≥ 25%	≥ 32%

How to take measurements

Neck: Measure just below the larynx, perpendicular to the neck axis
Waist: Measure at the narrowest point (males) or at the navel (females)
Hips (females only): Measure at the widest point

Example use cases

Fitness tracking: Monitor body composition progress during a training program
Health screening: A quick estimate without gym equipment
Goal setting: Determine a body fat percentage target for your fitness goals